Hey, I have an i4M50 as well and have had this happen 3 times already. I took it to the dealer for full analysis 2 weeks ago and they did a bunch of tests, drove it 80 miles and sent all the data to Germany with engineers giving it clean bill of health. I am thinking there is some type of issue with software but I am letting them know to look into this. I have noticed when I plug it in overnight at home and charge the message goes away. I would still make sure to at least have it checked out by the dealer if this is your first warning since want them to run full analysis, but I expect things will hopefully turn out well. Good luck